EuroRod

Which is a better indicator of the engines actual temperature, oil or coolant temps? I say coolant temps, but others argue oil? Anyone with some data?

Unreal

Oil IMO.

On my car coolant will hit ~180 in a few minutes, can take up to 15-20 minutes before oil temps get hot enough to beat on it.

carlrx7

Always been told coolant, if you are running the right viscosity oil then by the time the coolant hits temp, the oil is g2g. people that run straight weight oil are the ones that need to wait.

-Carl

Unreal

I guess it depends on the oil cooler setup. With the z06s huge air to air it takes forever in cooler weather for the oil temp to get up. That is running factory 5-30W. With the water/oil in the radiator the oil temp gets up a minute or two after the water temp is up since the water is heating the oil at that point.

Six-Gun-Todd

Oil

Oil is the only fluid coming in direct contact with engine internals....and you want piston wall clearances to be at operating spec before putting the coals to her.

tjwong

The OE cooler is OK, the reality is that it isn't that big especially the lines connected to it. I have been using the Setrab oil coolers supplied by Gary at ARE. These coolers are MUCH better and flows better especially when coupled with AN10 lines. The oil galleys in the LS engines are 5/8 ID or very near that, the stock GM cooler lines are just slightly larger than 3/8" ID. Talk about getting your oil to warm up fast, try one of these Setrab coolers, on the last Z I installed a complete ARE conversion on. The oil temps on an extended drive never got over 170. On a track car, my customer never saw it go past 225 when before with the OE GM cooler he had hit 275+ using M1 15/50 or Redline 20/50 synthetic oil.

NormWild

Always been my thought at well. I have my Oil Temp as my display on my HUD, won't put the throttle down until up to temp.

turbotuner20v

what do people consider up to temp for oil? 150*+?

EuroRod

I've heard that the F1 guys circulate 120* oil through their engines prior to starting them, so that's always been my mark. By the time the oil is at 120*, the coolant is 180+.

Streetk14

Well, the question I'd ask is: a better indicator of what? The oil and coolant do different jobs inside an engine, and can tell you different things.

Oil temp tells you about oil-lubricated parts (bearings, rings, etc), and should be what you use to decide if the engine is ready to be driven hard. Oil thickness changes a LOT depending on temperature, and even a 5W30 oil is much too thick during start-up than ideal.

Coolant temp tells you more about what's going on in the cylinder heads (combustion related). The coolant is also what tries to remove heat from the combustion chambers, oil and oil-lubricated parts.

zo6landrocket

Tom, where did you mount the Setrab oil coolers?

Detoxx03

Good question

Skunkworks

Your going to get lots of differing answers... but getting it hot enough to flash or boil off condensate (water) falls into consideration.

turbotuner20v

Isn't the flash point for mobile 1 5w30 like 225*?

Skunkworks

I was referring to removing contaminants like condensate (water). Normal boiling point is 212* (sea level or 14.69 PSIA). Refer to http://www.engineeringtoolbox.com/bo...ter-d_926.html for boiling point vs. pressure. As altitude goes up, boiling point comes down, same can be said with an effective PCV. So as an example if your at about 6000 ft water will boil around 200*.

Oil breaking down at 225* would be a bad thing, as I'm above that romping on it LOL. Safe oil temperature will turn into a really long topic fast.

EuroRod

Water doesn't have to be at 212* to evaporate. It is constantly evaporating. People think you have to get the oil temp up to 212* to evaporate condenstae from inside the engine. That is incorrect. Ever see fog on a pond? Doubt that water temp was 212*.

Skunkworks

True, but doesn't oil float on top of water? So would that be a barrier that inhibits or slows evaporation?